It has heretofore been commonly known to mount engines on a supporting frame by means of vibration-dampening motor mounts. Normally, such motor mounts are connected between the engine frame and to the body of the engine at several fore-and-aft positions and on opposite sides of the engine. It has also been known to mount a pulley on the main drive shaft of the engine through a flexible coupling so as to prevent the peak torsional loads of the devices being driven by the pulley from reverting back to the engine and also to dampen the impact of the V-belts upon starting or stopping the engine or upon a shock load occurring on the devices being driven. In small tractors, of what is commonly referred to as lawn and garden varieties, the engine, pulley, and the engine mounts must be located in a relatively small area. Due to the uses of such a tractor, it is preferred to keep all the weight out of the tractor that is possible. Also, due to the size of the tractor, it is particularly important to prevent the engine vibration from being transmitted to the frame and operator's station. Engine mounts are provided to dampen the vibrations created by the small, but relatively powerful engine. It is often difficult to find suitable locations to position the motor mounts extending between the engine and the tractor frame. In lawn and garden tractors, in general, there is no provision for dampening the torque load between the pulley and engine output shaft so that the vibrations of the shaft are generated to the various devices on the tractor and consequently, vibration does occur through the shaft, pulleys and belts that extend between the engine and the devices.
With the above in mind, it is the primary object of the present invention to provide a unique engine suspension system for a tractor that includes a pair of motor mounts on opposite sides of the tractor and generally on a specific center of gravity of the engine. Provided also is a pulley device in which the pulley is concentric with the main drive shaft of the engine and which is supported by a bearing that carries the pulley on the frame. The pulley has internal surfaces that are spaced from the shaft of the drive shaft and there is provided an annular layer of elastomer material which extends between the drive shaft and the pulley. The elastomer layer serves as a vibration dampener between the pulley shaft and the tractor frame and also as a flexible drive to the pulley which will dampen peak and sock loads on the devices to be driven by the tractor. Thus, the entire engine, including its main drive shaft, is supported by a vibration-dampening system on the tractor frame and the drive from the main drive shaft to the various devices is also dampened. Therefore, the vibrations created by the engine will be felt very little by an operator on the tractor. By providing the pair of direct motor mounts between the engine and the engine frame to be on the center of gravity, the dampening support between the shaft and the tractor frame needs merely to balance the engine at its forward end and will carry very little of the load created by the weight of the engine.